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Changing brake pads on WRX

229K views 152 replies 72 participants last post by  15WREX 
#1 ·
Changing brake pads

My front brake pads finally gave up the ghost this last week at ~18,000 miles. While I was changing them, I noticed that the pads are retained a little differently than all the other vehicles I have worked on. Henceforth, it seemed like it might be worthwhile for me to document the procedure...
 
#52 ·
You should have no problem using the existing backing plates. You need one metal clip (which is actually the brake wear sensor) for each caliper. If goes on the bottom end of the inside brake pad if I remember correctly. If you're only doing front or rear brake (hence the 4 pads?), then you only need two clips. The backing plates have their own little clips that hold them on the pad. By the way, if you ordered your pads from Stoptech.com, and there aren't enough wear sensors, just let them know. They'll send you more for free - right away! :)

Edit: Oh yeah, and the sharp edge of the wear sensor (clip) faces the caliper, because it scrapes on it when the pad wears down too much.
 
#53 ·
i just changed the brakes on my '99 outback wagon 2 days ago. i have to admit, the instructions were excellent, with the pictures to boot. Much props there. Anyway, i didnt read all of the replies, so i dont know if this has been iterated yet, but im just going to throw out a few tips i learned from the guys i know at the local mechanics shop down the road.

1. While the lugs are easy to get off, the caliper bolts are a *****. The solution is to take first spray the bolts with stuff called PB Blaster. Its much better than WD-40.

2. Then, take your trust sears (garbage) ratchet, and slide a 10 - 12 inch pipe over the handle. I never thought i would ever need physics class, but here i used it to solve my lack of putting torque to the bolts. TORQUE = FORCE x DISTANCE <--lever arm length, so having a bigger handle will allow you to put more torque into getting the bolts off if you pull at the end of the pipe.

3. Counter-clockwise the ratchet should feel resistance if you want to take bolts off. Clockwise puts them back on.

COMPRESSING THE CALIPER PISTONS

I just wanted to say, that the part in the original diy about taking off your brake resevior cap is not necessary at all.
When you have your caliper off, and your new brakes fitted, in order to get the caliper over the new brakes you need to compress the caliper pistons.
To do this, get a C-CLAMP from the local hardware store.
Now, take and position an old brake pad over the caliper pistons. This is while the caliper is still removed from its home. Then, clamp the old brake pad on the piston side to the caliper.
Tighten until you cant tighten anymore.

Now you can easily slide the caliper over the new brake pads. Do that, then bolt everything back up.

Start your car. Give it a min, then repeatedly stomp the brake pedal. The first time you hit the brakes (only hit the brakes when everything is back together and youre ready to drive away), you will feel the pedal hit the floor. Dont worry, its just the caliper pistons adjusting to the new pads from being compressed back into their housings. After about 10 stomps, your brake pedal should feel normal.

Take the car into a deserted street and get it going at 30 mph. Then smash the brakes just to make sure they work.


-James
 
#54 ·
I just read this post AFTER the fact. I did all 4 brakes yesterday and put in SS lines while I was at it. The instructions I read said nothing about greasing the backing plates. I re-used the ones that came with the old pads because Axxis doesn't give you any. How important is the grease on the back of the pad? I drove the car about 10 miles today and everything seems to work fine, and it doesn't make any noise. Do I need to take everything apart and grease them or not? When I took off the old pads it looked like if they were EVER greased the grease had long ago congealed or turned into a solid film...it deinately didn't feel greasy.
 
#56 ·
hey anyone help i have axxis brakes pads front and back for some reason i drove with them fine for like 3k miles after that the front brake makes loud noise when im not even braking i felt my front rotors and there not smooth there bumpy do i need to get new rotors would that help??

some one help please
 
#57 ·
Just installed new brake pads for the first time and here is something I learned to make things easier.

You do not need to take off the entire caliper. You only need to remove the bottom bolt and swing the caliper up. I got this info from a repair manual and it worked just fine. Very easy job to do.
 
#60 ·
Re-surfacing removes any grooves and "trues" up the rotor. If you went down to metal on the last set of pads you will have to do this at a minimum. You may have to replace rotors if they are too grooved or warped (i.e. out of spec). It is a good idea to resurface anyways but not absolutely necessary. Your brakes will work better and new pads will last longer. Personally, I'm just doing the pads as I will probably trade/sell the WRX in the next few months. Resurfacing the rotors involves removing them which is A LOT more work. Been there, done that. No thank you!
 
#61 ·
Quick li'l question here. I think two people have mentioned that you only need to remove the bottom bolt and swing the caliper up. I understand that makes it easy for working with putting the pads on and not having to deal with where the caliper falls. How do you get the caliper over the rotors with the new pads? Won't they be to close together? Or is it just a matter of working the pistons while its still bolted in? I'm going to give this a go tonight. Hopefully it won't take toooo long.

Joel
 
#62 ·
No need to take the whole caliper off, just swing it up. After you put the now pads on and before you swing the caliper back down, you'll need to compress the pistons back in all the way. That will allow you to swing the caliper back down with enough room to fit over the new pads.
 
#63 ·
Sotbas said:
No need to take the whole caliper off, just swing it up. After you put the now pads on and before you swing the caliper back down, you'll need to compress the pistons back in all the way. That will allow you to swing the caliper back down with enough room to fit over the new pads.

...and to compress the pistons in the calipers you can use a C-clamp or a brake pad compressor purchased from any place like Sears.
 
#65 ·
earlmale said:
to compress the pistons, i just used a screwdriver. it takes about 5 seconds- when you're doing it, you'll see what i'm talking about. just pry it some on both sides a couple of times with a flat head screwdriver.
Sure, you could do it that way but you will damage the piston. Some caliper pistons have a slot in them where you can turn them counter-clockwise to retract them (Honda) but I dont recall Subaru having the same design.
 
#67 ·
I forgot to update y'all...

So I changed my pads two weekends ago following these instructions. They were sooper helpful. Thanks!

I only unscrewed the bottom bolt, but loosened the top one so I could swing it up. Also, I used the lug wrench to work the pistons down. Worked like a charm. I finished up in just about an hour. Not bad for a first time by myself.

Joel
 
#72 ·
Going to do a pad replacement during this long 4th of July weekend.
It was briefly touched on in this forum that you can re-use the original plastic/metal plates for the pads, given that they have not been damaged from running the pads down too much. Is this also the case for the clips? I special ordered some Beck/Arnley Ceramic pads, and from what I was told, these pads were not going to come with new plates. I'm asking becuase it wouldn't surprise me if these pads are shipped w/o the clips as well.
Your collective input on ceramic pads is fully appreciated. These will be the first cermamic pads I've ever installed, hoping that they will be as strong and dust-free as they are said to be. If they aren't, I guess I'll be spending some time in a ditch somewhere in up-state VT.
 
#73 ·
fsidesmith said:
Going to do a pad replacement during this long 4th of July weekend.
It was briefly touched on in this forum that you can re-use the original plastic/metal plates for the pads, given that they have not been damaged from running the pads down too much. Is this also the case for the clips? I special ordered some Beck/Arnley Ceramic pads, and from what I was told, these pads were not going to come with new plates. I'm asking becuase it wouldn't surprise me if these pads are shipped w/o the clips as well.
Your collective input on ceramic pads is fully appreciated. These will be the first cermamic pads I've ever installed, hoping that they will be as strong and dust-free as they are said to be. If they aren't, I guess I'll be spending some time in a ditch somewhere in up-state VT.
yeah, mine came without any clips/backing plates. The instructions said to re-use them. You just spray them down with brake cleaner, REGREASE THEM, and put them on the new pads. I think there were spacers too.
 
#74 ·
change-up

Got my Beck/Arnleys this weekend and changed the pads up.
The Beck/Arnley ceramic pads didn't come with the caliper clips, but they do come with the plastic/metallic backing plates. I was a little surprised that they had a decal-type back adhesive. I assume Beck/Arnley's R&D guys found that an adhesive bond is a better squeak deterrent than grease. I still greased up the interface between the plastic/metallic plate and the outer stainless steel plate, as well as the backs of the caliper clips.
I was also surprised that the rear pads on the WRX have only one plate per pad by design (at least on my 2002). Even though the front calipers are larger to shoulder the majority of braking load, the rear calipers are still strong enough to really abuse the single-plates of the rear pads (my rear pad plates were slightly warped concave). FHI might want to consider revising this design if they haven't already.
Thanks for the step-by-step pace. Your photos were great, and the info on the caliper pistons was very helpful. I tried both methods, suggested by you and other Rexers in this thread, of pushing the pistons back. I personally found the loosening of the bleeder valve the easiest. Even without loosing the bleeder, the pistons are fairly easy to push back by hand with a lug wrench or small c-clamp. But without loosing the bleeder, you are prone to pushing brake fluid up into the system and overflowing DOT3 into the engine compartment and onto the floor (which I did).
After leaving a puddle of brake fluid in my garage, I started to worry about the fact that I was pushing back dirty fluid up the lines and into my system. So on the next caliper I removed the rubber plug and loosened the 8mm bleeder valve maybe a 1/4 or 1/2 turn. I found that I could push back the caliper piston much easier. You do need to be ready with a rag to catch about 1-2 shotglasses full of fluid. Once you've pushed the caliper as far as needed, be ready to tighten the bleeder valve back that 1/4 to 1/2 turn or you run the risk of getting air into the brake line. Still, the bleed-method is easier than it sounds.
After 50 miles or so, all is quiet and performing nicely. Not that they were really that bad before, but hopefully the ceramic pads keep my rims that much cleaner. Speaking of cleaner, pace's brake system was a hell of a lot cleaner and rust-free than mine was.
 
#75 ·
can someone plz go over the whole bleeding ur brakes bcuz my brakes have been squeking for a month or so but they dont squek all the time wen i break...i want to change them regardless and got performance brake pads...can anyone reiterate...oh and my pads just came w just the brake pads...is there anything i need to purchase to do this???
 
#76 ·
if you're changing just the pads, you shouldn't have to bleed the breaks. As I mentioned earlier, I just used a lug wrench to work the pistons back. when you pull off the old pads, there should be two plates on the back and a clip on the side. Those are the parts you need. you can just take them off and clean 'em.

-Joel
 
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